sin45*cos60+sin30*cos45=1/2[sin(45+60)+sin(45-60)]+1/2[sin(30+45)+sin(30-45)]=1/2[sin105+sin(-15)]+1/2[sin75+sin(-15)]=1/2[sin75-sin15]+1/2[sin75-sin15]=sin75-sin15=2[cos(75+15)/2][sin(75-15)/2]=2cos4...